The findings of the study, which was published in the British medical journal Lancet, place India at the top of the list of countries with the highest estimated number of adult TB cases associated with diabetes. India has the highest number of diabetic patients in the world and is also referred to as the world's TB capital. It is followed closely by China and South Africa.

"These findings highlight the growing impact of diabetes on TB control in countries where both diseases are prevalent," said Dr Knut Lonnroth, author of the study and a part of the global TB program, WHO in Geneva. He added, "TB control is being undermined by the growing number diabetes patients, which is expected to reach an astounding 592 million worldwide by 2035."

The study indicates that 15 percent of adult TB cases worldwide are attributable to diabetes. These diabetes-associated cases correspond to over 1 million cases a year, out of which, more than 40 percent occur in India and China. If diabetes continues to grow out of control, the downward trajectory in global TB cases could be offset by 8 percent or more by 2035, warn the authors of the study.